Cannot connect to projects

I am trying to connect to my projects, I am asked for the username and password on the login window and push OK.  Another login window appears and again I push okay; a third window appears stating "You could not login to project "ABC". Do you want to try again?"  I try various projects and receive the same results.  I have had this issue twice before but the problem seemed to rectify it's self within a hour or two; but not this time.  Myself and another user are experiencing the same issue, while the other two users are operating fine.

Any help with this is greatly appreciated.  I have tried to call the help desk but I keep getting disconnected after a ring or two.  I have logged a ticket but haven't heard back and this issue is becoming an increased priority.